1   /**
2    * Copyright (c) 2000-2009 Liferay, Inc. All rights reserved.
3    *
4    *
5    *
6    *
7    * The contents of this file are subject to the terms of the Liferay Enterprise
8    * Subscription License ("License"). You may not use this file except in
9    * compliance with the License. You can obtain a copy of the License by
10   * contacting Liferay, Inc. See the License for the specific language governing
11   * permissions and limitations under the License, including but not limited to
12   * distribution rights of the Software.
13   *
14   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20   * SOFTWARE.
21   */
22  
23  package com.liferay.portlet.words.util;
24  
25  import com.liferay.portlet.words.ScramblerException;
26  import com.liferay.portlet.words.util.comparator.WordComparator;
27  
28  import java.util.Set;
29  import java.util.TreeSet;
30  
31  /**
32   * <a href="Scrambler.java.html"><b><i>View Source</i></b></a>
33   *
34   * @author Brian Wing Shun Chan
35   */
36  public class Scrambler {
37  
38      public Scrambler(String word) throws ScramblerException {
39          if (word == null || word.length() < 3) {
40              throw new ScramblerException();
41          }
42  
43          _word = word;
44          _words = new TreeSet<String>(new WordComparator());
45      }
46  
47      public String[] scramble() {
48          if (_word == null) {
49              return new String[0];
50          }
51  
52          _scramble(0, _word.length(), _word.toCharArray());
53  
54          return _words.toArray(new String[_words.size()]);
55      }
56  
57      private void _rotate(char[] charArray, int start) {
58          char temp = charArray[start];
59  
60          for (int i = charArray.length - start -1; i > 0; i--) {
61              charArray[start] = charArray[++start];
62          }
63  
64          charArray[start] = temp;
65      }
66  
67      private void _scramble(int start, int length, char[] charArray) {
68          if (length == 0) {
69              String word = new String(charArray);
70  
71              for (int i = 3; i <= charArray.length; i++) {
72                  _words.add(word.substring(0, i));
73              }
74          }
75          else {
76              for (int i = 0; i < length; i++) {
77                  _scramble(start + 1, length - 1, charArray);
78                  _rotate(charArray, start);
79              }
80          }
81      }
82  
83      private String _word;
84      private Set<String> _words;
85  
86  }